Since the invention of the telephone and the pervasive use of telecommunications for exchanging information and conducting business, there has been a recognized need by private industry and government authorities for an ability to monitor selected telecommunications sessions.
Private industry routinely monitors selected telecommunications sessions, in particular voice communications, to evaluate the effectiveness of sales and customer service personnel to ensure that clients and/or potential clients receive adequate and courteous service in an attempt to maintain and increase market share. Because so many business transactions are now conducted by telephone, it is imperative that commercial operations have the ability to monitor their staff in an unobtrusive and undetectable fashion in order to ensure that an accurate evaluation of attitude and performance is obtained.
Selective monitoring of telecommunications is also conducted by government agencies, in particular law enforcement agencies in order to acquire information important in the maintenance of law and order. Since sophisticated tools are commercially available to permit the detection of monitoring equipment, law enforcement agencies require monitoring facilities which are difficult or impossible to detect in order to ensure that acquired information is accurate and reflective of information that would be exchanged in confidentiality.
A great deal of inventive ingenuity has been directed to providing systems for monitoring telecommunications sessions. Generally, prior art systems require that a "tap" consisting of a mechanical connection or bridge to monitoring equipment be attached to the telephone line to be monitored. This act of mechanically "tapping" into the monitored line is generally accomplished at a local telephone switch within the public switched telephone network or in a private branch exchange. A disadvantage of such monitoring equipment is that it changes the impedance on the monitored line and is readily detectable. Another disadvantage is that a great deal of time and effort is required to install such a monitoring connection. There is also a significant disadvantage for business in the lack of flexibility in this solution because the monitoring equipment is not readily switched from line to line. If, for example, a company wishes to monitor several sales persons randomly or sequentially, a prior art tap must be connected to each line used by the sales persons or the tap must be laboriously moved from line to line. The problem is further exacerbated if the sales persons use mobile equipment or have a Personal Number Service (PNS). In those instances, there is no practical solution for monitoring telecommunications sessions using such prior art equipment.
An automated and more flexible solution to communications monitoring is provided in U.S. Pat. No. 5,590,171 which issued to Howe et al on Dec. 31st, 1996. Howe et al provide a method and apparatus for allowing a communication from a calling party to a called party to be monitored and/or recorded by a monitoring party. The telephone switching system is equipped with Advanced Intelligent Network (AIN) capability which permits software triggers in the service switching points (SSPs) to respond to AIN triggers when a call is dialled to or from a designated line served by the network. The AIN trigger generates an appropriate message to be sent out over the Advanced Intelligent Network and suspends call handling until the SSP receives a reply from the network instructing the SSP to take certain action. If the SSP receives instructions to monitor the call, the SSP completes the call from the calling to the called party and then constructs a bridge to monitoring equipment which establishes a one-way line to a monitoring person or recording equipment such as a tape-recorder.
While this solution to the problem overcomes many disadvantages of the prior art, it too suffers from certain disadvantages. First, the query to a central AIN database for call routing instructions generally takes a minimum of 600 milliseconds. This introduces a perceptible delay in the call process which may be detected by the calling party. Second, because the bridge to the monitoring equipment is not constructed until the calling and the called party are connected, connection of the bridge can sometimes be audibly detected. A significant motivation for monitoring is defeated if the monitored employee is able to detect when their conversation is being monitored. Of course, any method of call monitoring is of substantially no value to law enforcement officials if either of the called or the calling parties is in any way able to detect the fact that the call is being monitored.